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On 2012-01-28 09:27:05 -0800, Mark F said:
On Wed, 25 Jan 2012 19:02:10 -0800, Savageduck
wrote:
This should provide some incentive for those who have yet to experience
Yosemite, to make that trip.http://vimeo.com/35396305
I don't understand how the meteor trails work: it seems like
meteor trails last too long. Did they:
1. photograph many more frames than were displayed and edit
to keep more frames from the brief times when trails were visible.
or
2. the field of view is so many miles that trail of a meteor
moving at perhaps 30 miles/second stay in view long enough
to look like a moving object? How far apart timewise were
the displayed frames at about 2:38? I'm bad at estimating things
and can't decide how many degrees per second things seem to be
moving. I couldn't find a technical description of the shoot.

I would say there are several things happening here.

1. The time lapse set at each location is taken over a long enough
period to include perceived movement of shadows over time, and the fact
that the cameras are not stationary. they are track mounted and move
throughout many of the sequences.

2. I have a feeling that the brain has been fooled into accepting that
all the light trails are in fact all meteor trails. I am very familiar
with Yosemite and it is located below some of the most trafficked
commercial & military aviation routes in the West. Routes between Los
Angeles and Europe pass over the area, as do routes from SFO,
Sacramento, & Fresno to and from Las Vegas, the South-West and other
Southern States. I have many shots of Yosemite in daylight where the
sky is filled with aircraft contrails. Also consider that there are
many directional changes for those captured light trails.
A check of various domestic routes show examples of Delta flights
between LA, Seattle, Portland, & Europe over flying Yosemite, as do
flights between SFO, Oakland & Atlanta.
When it comes to United Airlines they have 100's of flights between
SFO, Oakland, San Jose, Dallas, Las Vegas, Houston, Tucson, Phoenix,
Orlando, and destinations in South America, all fly over Yosemite.
That is just two of the many airlines flying similar routes.

My conclusion is, that while some brief flashes of meteor trails might
have been captured, the majority of what was seen were a mix of meteor
and mostly aircraft navigation lights, and the brain has been led to
believe it had seen nothing but meteor trails.

Mark F wrote:
On Wed, 25 Jan 2012 19:02:10 -0800, Savageduck
wrote:
This should provide some incentive for those who have yet to experience
Yosemite, to make that trip.http://vimeo.com/35396305
I don't understand how the meteor trails work: it seems like
meteor trails last too long. Did they:
1. photograph many more frames than were displayed and edit
to keep more frames from the brief times when trails were visible.
or
2. the field of view is so many miles that trail of a meteor
moving at perhaps 30 miles/second stay in view long enough
to look like a moving object? How far apart timewise were
the displayed frames at about 2:38? I'm bad at estimating things
and can't decide how many degrees per second things seem to be
moving. I couldn't find a technical description of the shoot.

I agree. Something not right here.
I have been an amateur astronomer for many years.
The sky on the videos moves per earth rotation but the
flashes continue straight. They are moving very slowly,
what ever they are, just a few mph.

Many are identical repeats. Meteors often never make it from
horizon to horizon. They fade out.
I don't see any flashing marker lights from very slow moving
aircraft or weather balloons.
Something tells me that many of the effects are digitally
drawn in later. And not just on the night vids.
Nice vids, but not real.

Many are identical repeats. Meteors often never make it from
horizon to horizon. They fade out.
I don't see any flashing marker lights from very slow moving
aircraft or weather balloons.
Something tells me that many of the effects are digitally
drawn in later. And not just on the night vids.
Nice vids, but not real.

Most I saw were obviously aircraft flying over.
I think the reason you don't notice the marker lights
is that they were using long exposures and the markers
tend to blend together to make one long streak.
They only look like repeats because they are all flying
the same airways. IE: J58-80 runs right across the park
a bit north of Mammoth Lakes running E-W on a line
pretty much from Oakland to Manteca, and then over to
Coaldale NV. There are others, and also an intersection
pretty much right over the park. Some may make turns
at that intersection. The planes flying regular jet airways
airways will not be flying perfect tracks, but pretty
danged close to someone watching from below.
If the planes are using RNP navigation, they will show almost
perfect tracks over the same routes being as the lateral error
is so low.
The Southwest jets I run on my sim are RNP equipped.
The lateral navigation is so accurate that if I were to
approach an airport using an RNP approach, I won't fly
over the same neighborhood every time, I'll fly over the
same houses in that neighborhood every time.
Anyway, to my beady eyeballs, those are all aircraft, with
a few meteors thrown in every once in a while.
Naturally, the meteors don't run from horizon to horizon
like the aircraft do, but fizzle out pretty fast.

Many are identical repeats. Meteors often never make it from
horizon to horizon. They fade out.
I don't see any flashing marker lights from very slow moving
aircraft or weather balloons.
Something tells me that many of the effects are digitally
drawn in later. And not just on the night vids.
Nice vids, but not real.

Most I saw were obviously aircraft flying over.
I think the reason you don't notice the marker lights
is that they were using long exposures and the markers
tend to blend together to make one long streak.
They only look like repeats because they are all flying
the same airways. IE: J58-80 runs right across the park
a bit north of Mammoth Lakes running E-W on a line
pretty much from Oakland to Manteca, and then over to
Coaldale NV. There are others, and also an intersection
pretty much right over the park. Some may make turns
at that intersection. The planes flying regular jet airways
airways will not be flying perfect tracks, but pretty
danged close to someone watching from below.
If the planes are using RNP navigation, they will show almost
perfect tracks over the same routes being as the lateral error
is so low.
The Southwest jets I run on my sim are RNP equipped.
The lateral navigation is so accurate that if I were to
approach an airport using an RNP approach, I won't fly
over the same neighborhood every time, I'll fly over the
same houses in that neighborhood every time.
Anyway, to my beady eyeballs, those are all aircraft, with
a few meteors thrown in every once in a while.
Naturally, the meteors don't run from horizon to horizon
like the aircraft do, but fizzle out pretty fast.

Mark F wrote:
On Wed, 25 Jan 2012 19:02:10 -0800, Savageduck
wrote:
This should provide some incentive for those who have yet to experience
Yosemite, to make that trip.http://vimeo.com/35396305
I don't understand how the meteor trails work: it seems like
meteor trails last too long.

They're not meteor trails. Yosemite is under a major air corridor
from the Bay Area to the East. Those are jet airliners. You can also
see the contrails in several of the daytime shots (@2:19, e.g.)

--
Ray Fischer | None are more hopelessly enslaved than those who falsely believe they are free. | Goethe

On 1/28/2012 12:27 PM, Mark F wrote:
On Wed, 25 Jan 2012 19:02:10 -0800, Savageduck
wrote:
This should provide some incentive for those who have yet to experience
Yosemite, to make that trip.
http://vimeo.com/35396305
I don't understand how the meteor trails work: it seems like
meteor trails last too long. Did they:
1. photograph many more frames than were displayed and edit
to keep more frames from the brief times when trails were visible.
or
2. the field of view is so many miles that trail of a meteor
moving at perhaps 30 miles/second stay in view long enough
to look like a moving object? How far apart timewise were
the displayed frames at about 2:38? I'm bad at estimating things
and can't decide how many degrees per second things seem to be
moving. I couldn't find a technical description of the shoot.

They're not meteor trails. Yosemite is under a major air corridor
from the Bay Area to the East. Those are jet airliners. You can also
see the contrails in several of the daytime shots (@2:19, e.g.)
The daytime shot around 2:19 are contrails - they disperse over time;
the nighttime shots don't disperse and start within the field of view.

Look again.

They are aircraft light trails, the air traffic over yosemite is quite
dense, and moves on several different compass points. Over Yosemite
there are reciprocal routes running SSW-NNE, SW-NE, NW-SE, E-W, with
several hundred flights running around the clock. Then there are
military flights running from Beale AFB, NAS Lemore in California,
Nellis AFB, NAS Fallon in Nevada, and the USMC Mountain Warfare
Training Center which lies about 37 miles due North of Yosemite Valley
and flies VSTOL and helicopter operations in the area. All of these
military bases fly missions taking them across, and around the Sierras
in the area of Yosemite.

Ray Fischer wrote:
Mark F wrote:
On Wed, 25 Jan 2012 19:02:10 -0800, Savageduck
wrote:
This should provide some incentive for those who have yet to experience
Yosemite, to make that trip.http://vimeo.com/35396305
I don't understand how the meteor trails work: it seems like
meteor trails last too long.

They're not meteor trails. Yosemite is under a major air corridor
from the Bay Area to the East. Those are jet airliners. You can also
see the contrails in several of the daytime shots (@2:19, e.g.)

Now it would be really interesting if we saw some making right angle turns
or loop de loops.